Bryant 352MAV User Manual

Page 8

box. The screw in the bracket is always located toward
outside of burner box. The screw may be hidden by inlet
box or inlet pipe, but can be removed without removing
either. After removing screw, slide ignitor and bracket
toward outside of burner box and pull straight out.

CAUTION:

The ignitor is fragile. DO NOT allow it to

hit the side of the burner box opening while removing or
replacing it.

b. Inspect ignitor for a white area indicating a crack may be

present. If found, replace ignitor.

NOTE:

A small crack cannot be seen on a new ignitor. After a

period of operation, a white area will be visible around the crack.

c. If replacement is required, replace ignitor on ignitor

bracket external to furnace to avoid damage as the
silicon portion is very brittle and will easily crack or
shatter.

d. To remove ignitor from ignitor bracket, remove screw

holding ignitor ceramic block to bracket and pull ce-
ramic block out of bracket.

6. To replace ignitor/ignitor assembly, reverse items 5a

through 5d.

7. Reconnect ignitor wire connection.

8. Turn on gas and electrical supplies to furnace.

9. Verify ignitor operation by initiating control board self-test

feature or by cycling thermostat.

10. Replace main furnace door.

VII.

ELECTRICAL CONTROLS AND WIRING

CAUTION:

There may be more than 1 electrical supply

to the unit. Check accessories and cooling unit for
additional electrical supplies.

The electrical ground and polarity for 115-v wiring must be
maintained properly. Refer to Fig. 11 for field wiring information
and to Fig. 15 for unit wiring information.

NOTE:

If the polarity is not correct, the STATUS LED on the

control will flash rapidly and prevent the furnace from operating.
The control system also requires an earth ground for proper
operation of the control and flame sensing.
The 24-v circuit contains an automotive-type, 3-amp fuse located
on the control center. (See Fig. 11.) Any direct shorts of the 24-v
wiring during installation, service, or maintenance will cause this
fuse to blow. If fuse replacement is required, use ONLY a 3 amp
fuse. The control LED will display status code 24 when fuse needs
to be replaced.
With power to the unit disconnected, check all electrical connec-
tions for tightness. Tighten all screws on electrical connections. If
any smoky or burned connections are found, disassemble the
connection, clean all parts, strip wire, and reassemble properly and
securely.
Reconnect electrical supply to unit and observe unit through 1
complete operating cycle. Electrical controls are difficult to check
without proper instrumentation; if there are any discrepancies in
the operating cycle, contact your dealer and request service.

VIII.

CHECKING HEAT TAPE OPERATION (IF APPLI-

CABLE)

In applications where the ambient temperature around the furnace
is 32° or lower, freeze protection measures are required. If this
application is where heat tape has been applied, check to ensure it
will operate when low temperatures are present.

Fig. 11—Field Wiring

A98325

115-V

FIELD-SUPPLIED

DISCONNECT

SWITCH

115-V

SINGLE

PHASE

AUXILIARY
J-BOX

FURNACE

CONTROL

CENTER

TWO WIRE

24-V

TERMINAL

BLOCK

THREE-WIRE

HEATING

ONLY

FIVE

WIRE

NOTE 5

NOTE 1

NOTE

THERMOSTAT
TERMINALS

FIELD-SUPPLIED

DISCONNECT

CONDENSING

UNIT

GND

FIELD 24-V WIRING
FIELD 115-, 208/230-, 460-V WIRING
FACTORY 24-V WIRING
FACTORY 115-, 208/230-, 460-V WIRING

208/230- OR

460-V

THREE PHASE

208/230-V

SINGLE

PHASE

W/W1

Y/Y2

NOTES:

1.
2.
3.
4.

Connect Y or Y/Y2 terminal as shown for proper cooling operation.
Proper polarity must be maintained for 115-v wiring.
Use W2 with 2-stage thermostat when zoning.
If any of the original wire, as supplied, must be replaced, use
same type or equivalent wire.
Some thermostats require a "C" terminal connection as shown.

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